Abstract
This cross-sectional study examines whether an increase in immigration enforcement activity in Los Angeles County during June 2025 was associated with changes in emergency department and inpatient utilization by patient country of birth.
Introduction
After the 2025 inauguration, a new presidential administration increased immigration enforcement and anti-immigration rhetoric across the US. Los Angeles County, where nearly 10% of the population is undocumented, was a target of well-publicized raids. Existing evidence shows that increased anti-immigration rhetoric and immigration enforcement is associated with decreased health care use among immigrant populations.1,2,3,4,5 Avoidance of care is subsequently associated with worse outcomes.6,7
This study evaluates whether there were differential changes in emergency department (ED) and inpatient utilization at Los Angeles County safety-net hospitals by patient self-reported country of birth before and after increased immigration enforcement activity in June 2025. These hospitals serve large immigrant (documented and undocumented) populations; nearly one-third of ED visits come from undocumented patients.8
Methods
This retrospective, cross-sectional study examined encounter-level data from electronic health records for adult patients from 3 safety-net hospital emergency and inpatient departments in Los Angeles County between June 6, 2024, and October 15, 2025. We estimated weekly ED encounters and inpatient admission rates from the ED (eTable 1 in Supplement 1) by patient self-reported region of birth (eTable 2 in Supplement 1) before and after the beginning of increased immigration enforcement activity. Country of birth is recorded during any prior encounters, at ED registration, during a stay, or at subsequent encounters. Populations born in Mexico, and Central or South America have a high likelihood of being undocumented or being members of mixed-status households.9 The pre-enforcement period extended from June 6, 2024, to June 4, 2025; the post-enforcement period began June 5, 2025, the day before several sweeps across the region and an associated increase in immigration-related detentions.10
We used difference-in-differences event study regressions to compare outcomes before and after increased enforcement for individuals born in or outside of the US. Regressions controlled for enforcement period, region of birth, and their interaction. Additional analyses examined variation by specific country or region of birth and time relative to the onset of increased enforcement (eMethods in Supplement 1). This study was deemed exempt from review and informed consent by the University of Southern California institutional review board. This study followed the STROBE reporting guidelines.
Results
The hospitals in our study had a mean (SD) of 1943 (102) weekly ED visits for US-born, 1301 (100) for Mexican-born, 850 (60) for Central or South American–born, and 216 (21) for Asian-born patients prior to increased enforcement (Table). After increased enforcement, there was no change in ED visits among US-born patients, but a marked decrease in ED visits among those born outside the US (Figure, A and B). Inpatient admission rates from the ED, including transfers to other hospitals, had a mean (SD) of 27.6% (1.8%) for US-born, 20.3% (2.8%) for Mexican-born, and 16.1% (2.4%) for Central and South American–born patients prior to increased enforcement (Table). After increased enforcement, inpatient admission rates rose for those born outside the US, with little change for the US-born population (Figure, C and D). Statistical testing showed no difference in pre-enforcement trends in either outcome.
Table. Difference-in-Differences Analysis of Weekly Emergency Department Visits and Inpatient Admission Rates by Region of Birtha.
| Model | ED visits per week | Weekly emergency department to inpatient admission rate | ||||||
|---|---|---|---|---|---|---|---|---|
| Unadjusted mean (SD), No. | Difference-in-differences estimate (95% CI) | Unadjusted mean (SD), % | Difference-in-differences estimate (95% CI) | |||||
| Pre | Post | Unadjusted | Adjusted | Pre | Post | Unadjusted | Adjusted | |
| Baseline | ||||||||
| US | 1943 (102) | 2023 (69) | 1 [Reference] | 1 [Reference] | 27.6 (1.8) | 25.6 (1.0) | 0 [Reference] | 0 [Reference] |
| Mexico | 1301 (100) | 1204 (74) | −178 (−223.74 to −133.12) | −177 (−235.40 to −119.00) | 20.3 (2.8) | 23.0(1.6) | 4.78 (2.24 to 7.32) | 4.75 (3.53 to 5.97) |
| Central or South America | 850 (60) | 763 (51) | −167 (−212.66 to −122.04) | −161 (−210.32 to −112.63) | 16.1 (2.4) | 19.3 (1.7) | 5.21 (2.67 to 7.75) | 5.1 (3.88 to 6.33) |
| Asia | 216 (21) | 206 (17) | −91 (−136.09 to −45.48) | −98 (−141.55 to −54.45) | 27.7 (3.6) | 27.6 (4.1) | 1.9 (−0.64 to 4.44) | 2.49 (0.28 to 4.70) |
| Other | 142 (14) | 143 (11) | −80 (−124.95 to −34.34) | −84 (−126.52 to −41.80) | 22.9 (4.1) | 23.4 (3.9) | 2.46 (−0.08 to 5.01) | 2.93 (0.70 to 5.15) |
| Missing | 198 (26) | 177 (15) | −102 (−147.46 to −56.84) | −98 (−142.43 to −54.39) | 38.0 (4.9) | 41.0 (5.2) | 5.02 (2.48 to 7.56) | 5.37 (2.58 to 8.16) |
| Dynamic | ||||||||
| 1-4 wk Postenforcement | ||||||||
| US | 1943 (102) | 2043 (50) | 1 [Reference] | 1 [Reference] | 27.6 (1.8) | 26.5 (0.2) | 0 [Reference] | 0 [Reference] |
| Mexico | 1301 (100) | 1126 (85) | −276 (−362.95 to −188.94) | −277 (−370.16 to −183.14) | 20.3 (2.8) | 24.5 (2.7) | 5.32 (0.50 to 10.14) | 5.18 (2.89 to 7.46) |
| Central or South America | 850 (60) | 706 (36) | −244 (−330.74 to −156.72) | −243 (−304.04 to −182.37) | 16.1 (2.4) | 20.1 (1.6) | 5.12 (0.30 to 9.95) | 5.21 (3.45 to 6.98) |
| Asia | 216 (21) | 205 (19) | −112 (−198.66 to −24.65) | −124 (−179.43 to −68.23) | 27.7 (3.6) | 29.2 (3.9) | 2.69 (−2.13 to 7.51) | 3.4 (−0.24 to 7.04) |
| Other | 142 (14) | 149 (8) | −94 (−180.68 to −6.67) | −95 (−145.73 to −43.38) | 22.9 (4.1) | 26.3 (2.1) | 4.5 (−0.32 to 9.32) | 4.83 (3.12 to 6.55) |
| Missing | 198 (26) | 165 (7) | −134 (−220.99 to −46.97) | −133 (−190.11 to −76.80) | 38.0 (4.9) | 41.5 (4.7) | 4.69 (−0.13 to 9.52) | 4.99 (0.45 to 9.53) |
| 5-8 wk Postenforcement | ||||||||
| US | 1943 (102) | 2056 (47) | 1 [Reference] | 1 [Reference] | 27.6 (1.8) | 25.5 (0.7) | 0 [Reference] | 0 [Reference] |
| Mexico | 1301 (100) | 1184 (70) | −231 (−317.95 to −143.94) | −229 (−313.24 to −145.40) | 20.3 (2.8) | 23.6 (0.9) | 5.38 (0.56 to 10.21) | 5.38 (3.92 to 6.85) |
| Central or South America | 850 (60) | 760 (44) | −203 (−290.24 to −116.22) | −198 (−261.27 to −134.09) | 27.7 (3.6) | 28.2 (5.5) | 5.47 (0.65 to 10.29) | 5.43 (4.13 to 6.74) |
| Asia | 216 (21) | 205 (19) | −124 (−211.16 to −37.15) | −137 (−195.39 to −78.27) | 16.1 (2.4) | 19.5 (1.0) | 2.65 (−2.17 to 7.47) | 3.45 (−1.40 to 8.30) |
| Other | 142 (14) | 139 (9) | −117 (−203.68 to −29.67) | −129 (−183.91 to −73.83) | 22.9 (4.1) | 26.3 (4.0) | 5.46 (0.64 to 10.28) | 6.27 (2.56 to 9.98) |
| Missing | 198 (26) | 167 (12) | −145 (−231.74 to −57.72) | −151 (−211.44 to −91.33) | 38.0 (4.9) | 46.8 (2.9) | 10.89 (6.07 to 15.71) | 11.47 (8.30 to 14.63) |
| 9-12 wk postenforcement | ||||||||
| US | 1943 (102) | 2056 (66) | 1 [Reference] | 1 [Reference] | 27.6 (1.8) | 25.0 (1.1) | 0 [Reference] | 0 [Reference] |
| Mexico | 1301 (100) | 1261 (24) | −153 (−240.20 to −66.19) | −156 (−230.05 to −80.99) | 20.3 (2.8) | 22.4 (0.8) | 4.72 (−0.10 to 9.54) | 4.88 (3.33 to 6.44) |
| Central or South America | 850 (60) | 779 (31) | −183 (−270.24 to −96.22) | −176 (−247.22 to −105.08) | 27.7 (3.6) | 27.4 (3.4) | 6.4 (1.61 to 11.25) | 6.22 (4.63 to 7.82) |
| Asia | 216 (21) | 207 (12) | −122 (−208.91 to −34.90) | −128 (−197.07 to −59.52) | 16.1 (2.4) | 20.0 (0.9) | 2.28 (−2.54 to 7.10) | 2.84 (−0.74 to 6.42) |
| Other | 142 (14) | 150 (10) | −105 (−191.68 to −17.67) | −126 (−195.07 to −56.91) | 22.9 (4.1) | 21.9 (3.0) | 1.51 (−3.31 to 6.34) | 2.55 (−0.68 to 5.79) |
| Missing | 198 (26) | 179 (18) | −133 (−219.74 to −45.72) | −142 (−211.94 to −72.62) | 38.0 (4.9) | 37.1 (1.9) | 1.69 (−3.13 to 6.51) | 1.93 (−0.83 to 4.69) |
| ≥13 wk Postenforcement | ||||||||
| US | 1943 (102) | 1975 (72) | 1 [Reference] | 1 [Reference] | 27.6 (1.8) | 25.4 (1.1) | 0 [Reference] | 0 [Reference] |
| Mexico | 1301 (100) | 1227 (54) | −107 (−174.63 to −39.61) | −103 (−177.14 to −28.36) | 20.3 (2.8) | 22.3 (1.2) | 4.15 (0.41 to 7.89) | 4.06 (2.59 to 5.53) |
| Central or South America | 850 (60) | 788 (52) | −94 (−161.63 to −26.61) | −84 (−153.39 to −15.47) | 27.7 (3.6) | 26.3 (4.3) | 4.4 (0.66 to 8.15) | 4.17 (2.24 to 6.10) |
| Asia | 216 (21) | 206 (21) | −42 (−109.52 to 25.50) | −42 (−103.67 to 19.26) | 16.1 (2.4) | 18.3 (2.1) | 0.8 (−2.94 to 4.54) | 1.21 (−2.16 to 4.59) |
| Other | 142 (14) | 138 (13) | −36 (−103.68 to 31.34) | −27 (−85.43 to 30.99) | 22.9 (4.1) | 20.9 (3.2) | 0.14 (−3.61 to 3.88) | 0.12 (−2.76 to 3.00) |
| Missing | 198 (26) | 189 (10) | −42 (−109.67 to 25.35) | −20 (−80.61 to 41.55) | 38.0 (4.9) | 39.6 (5.5) | 3.76 (0.02 to 7.50) | 3.98 (−0.00 to 7.96) |
Other region of birth is defined in eTable 2 in Supplement 1. Unknown or missing country of birth accounts for 4.2% of emergency department encounters. The baseline models include an indicator for the postenforcement period, region of birth, and their interaction. The dynamic models include indicators for 1 to 4, 5 to 8, 9 to 12, and 13 or more weeks since the initiation of the postenforcement period, region of birth, and their interaction. Adjusted models also control for mean age and share of patients who are male.
Figure. Line Graphs of Unadjusted and Adjusted Estimates of Emergency Department (ED) Visits and Admissions Rates From the ED by Week Relative to Increased Immigration and Region of Birth.
The decrease in ED visits prior to the increased immigration enforcement (week −7) was the result of a nursing strike at all the hospitals under study. The hospitals were effectively closed to emergencies and were not admitting new patients. Details on the nursing strike are included in the eMethods in Supplement 1. Adjusted estimates control for week fixed effects, region of birth fixed effects, and region-specific linear time trends for the pre-enforcement period.
Regression results showed a relative reduction (vs US-born patients) of 177 (95% CI, −235 to −119) weekly visits for Mexican-born patients, 161 (95% CI, −210 to −113) for Central or South American–born patients, and 98 (95% CI, −142 to −54) for Asian-born patients in the postenforcement period. These reductions attenuated over time but remained significantly lower 12 weeks after enforcement began (Table).
Despite fewer ED visits, the admission rate of patients born outside the US increased relative to US-born counterparts. Difference-in-differences estimates showed that compared with US-born patients, admission rates for Mexican-born patients increased 4.8 (95% CI, 3.5-6.0) percentage points, Central or South American–born admission rates increased 5.1 (95% CI, 3.9-6.3) percentage points, and Asian-born admission rates increased 2.5 (95% CI, 0.3-4.7) percentage points (Table). These relative increases for Mexican and Central or South American–born patients were observed the entire postenforcement window.
Discussion
In this study, increased immigration enforcement was associated with sharp, persistent decreases in ED visits among patients born outside the US and relative increases in inpatient admission rates compared with US-born patients. Lower ED utilization indicates that patients were less likely to seek care during increased immigration enforcement in the community. While ED utilization was lower throughout our study, the magnitude of the difference halved from a more-than-20% reduction in the first 4 weeks to a 10% reduction in visits by the end of our study period. In contrast to lower ED utilization, higher inpatient admission rates likely signal that patients who presented to the ED had higher acuity, consistent with delayed care-seeking or fewer nonurgent ED visits, bolstering inpatient admissions rates to reflect a higher number of acute visits. Relative increases in inpatient admission rates remained stable for the postenforcement period.
This study’s limitations include its reliance on self-reported country of birth and inability to differentiate between undocumented and documented immigrants. We did not observe nor control for encounter acuity.
Together with other studies reporting similar results,1 our findings suggest that heightened immigration enforcement may lead to avoidance of acute care among immigrant patients, with potential negative health and economic consequences for patients and the systems who care for them.
eTable 1. Definitions of ED Visits and ED to Inpatient Admissions
eTable 2. Definitions of Region of Birth
eMethods.
Data Sharing Statement
References
- 1.Bao J, Sun L, Nguyen-Hoang P, Momany ET. Exploring the effect of anti-immigration rhetoric on emergency department use by undocumented adults. J Immigr Minor Health. 2024;26(1):110-116. doi: 10.1007/s10903-023-01531-z [DOI] [PubMed] [Google Scholar]
- 2.Saadi A, Taleghani S, Hampton K, Heisler M. Clinicians’ perspectives on the impacts of post-2016 immigration enforcement on immigrant health and health care use. J Health Care Poor Underserved. 2021;32(4):1778-1797. doi: 10.1353/hpu.2021.0166 [DOI] [PubMed] [Google Scholar]
- 3.Ettinger de Cuba S, Miller DP, Raifman J, et al. Reduced health care utilization among young children of immigrants after Donald Trump’s election and proposed public charge rule. Health Aff Sch. 2023;1(2):qxad023. doi: 10.1093/haschl/qxad023 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Martinez O, Wu E, Sandfort T, et al. Evaluating the impact of immigration policies on health status among undocumented immigrants: a systematic review. J Immigr Minor Health. 2015;17(3):947-970. doi: 10.1007/s10903-013-9968-4 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Toomey RB, Umaña-Taylor AJ, Williams DR, Harvey-Mendoza E, Jahromi LB, Updegraff KA. Impact of Arizona’s SB 1070 immigration law on utilization of health care and public assistance among Mexican-origin adolescent mothers and their mother figures. Am J Public Health. 2014;104(Suppl 1)(suppl 1):S28-S34. doi: 10.2105/AJPH.2013.301655 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Jones S, Moulton C, Swift S, et al. Association between delays to patient admission from the emergency department and all-cause 30-day mortality. Emerg Med J. 2022;39(3):168-173. doi: 10.1136/emermed-2021-211572 [DOI] [PubMed] [Google Scholar]
- 7.Nguyen OK, Vazquez MA, Charles L, et al. Association of scheduled vs emergency-only dialysis with health outcomes and costs in undocumented immigrants with end-stage renal disease. JAMA Intern Med. 2019;179(2):175-183. doi: 10.1001/jamainternmed.2018.5866 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Ro A, Huynh MP, Bruckner TA, Du S, Young A. COVID-19 case counts and COVID-19 related emergency department visits: differences by immigration status, March-December 2020. BMC Public Health. 2022;22(1):1965. doi: 10.1186/s12889-022-14345-9 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Data Hub. California Immigrant Data Portal. 2026. Accessed June 25, 2026. https://www.immigrantdataca.org/data-hub
- 10.Blair G, Hausman D, Neff P. Immigration and Customs Enforcement individual-level administrative data. Deportation Data Project. December 2025. Accessed August 24, 2026. https://deportationdata.org/docs/ice/ice-data-preprint.pdf
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
eTable 1. Definitions of ED Visits and ED to Inpatient Admissions
eTable 2. Definitions of Region of Birth
eMethods.
Data Sharing Statement
